ios - UIAlertcontroller设置属性消息

如何在UIAlertcontroller中将属性文本设置为消息。
我的尝试代码如下，但是它将使应用程序崩溃。

// create Attributed text

let myAttribute = [NSForegroundColorAttributeName: UIColor(red:122.0/255, green:125.0/255, blue:131.0/255, alpha:1.0),NSFontAttributeName: Constant.flinntRegularFont(15)]
let myAttribute2 = [NSForegroundColorAttributeName: UIColor.blackColor(),NSFontAttributeName: Constant.flinntMediumFont(15)]

let myString = NSMutableAttributedString(string: "You have been unsubscribed from ", attributes: myAttribute)
let myString2 = NSMutableAttributedString(string: self.course.course_name, attributes: myAttribute2)
let myString3 = NSMutableAttributedString(string: "\n\nYour refund will be initiated within one week.", attributes: myAttribute)
let myString4 = NSMutableAttributedString(string: "\n\nFor any help call us on", attributes: myAttribute)
let myString5 = NSMutableAttributedString(string: " 079-4014 9800", attributes: myAttribute2)
let myString6 = NSMutableAttributedString(string: " between 9:30 am to 6:30 pm on Monday to Saturday.\n\nWe will be always here with great deals to share.", attributes: myAttribute)

myString.appendAttributedString(myString2)
myString.appendAttributedString(myString3)
myString.appendAttributedString(myString4)
myString.appendAttributedString(myString5)
myString.appendAttributedString(myString6)

当前的UIAlertcontroller代码

let alert = UIAlertController(title: "", message: "Select course", preferredStyle: UIAlertControllerStyle.Alert)
    alert.setValue(myAttribute, forKey: "attributedMessage") // this line make a crash.

    alert.addAction(UIAlertAction(title: "OK", style: .Cancel, handler: { (action) in
        self.delegate?.courseRefundViewControllerCoursrRefunded?(self)
        self.navigationController?.popViewControllerAnimated(true)
    }))
self.presentViewController(alert, animated: true, completion: nil)

谢谢。

最佳答案

您的应用因数据类型不匹配而崩溃。
alert.setValue(<value>, forKey: "attributedMessage")
这里<value>必须是NSMutableAttributedString的实例。

但是，您传递的是Dictionary的myAttribute。

它正在尝试调用length方法，但在Dictionary上找不到它，这就是应用崩溃的原因。

试试这个:

alert.setValue(myString, forKey: "attributedMessage")